The response of benthic foraminifera to various pollution sources: a study from Nellore Coast, East Coast of India

Impact of pesticides on marine coral reef foraminifera

Our laboratory study looked into how pesticides affect the foraminifera species Heterostegina depressa and their obligatory algal endosymbionts. We incubated the foraminifera separately with different types of pesticides at varying concentrations (1 %, 0.01 % and 0.0001 %); we included the insecticide Confidor© (active substance: imidacloprid), the fungicide Pronto©Plus (tebuconazole), and the herbicide Roundup© (glyphosate). Our evaluation focused on the symbiont's photosynthetically active area (PA), and the uptake of dissolved inorganic carbon (DIC) and nitrogen (nitrate) to determine the vitality of the foraminifera. Our findings showed that even the lowest doses of the fungicide and herbicide caused irreparable damage to the foraminifera and their symbionts. While the insecticide only deactivated the symbionts (PA = 0) at the highest concentration (1 %), the fungicide, and herbicide caused complete deactivation even at the lowest levels provided (0.0001 %). The fungicide had the strongest toxic effect on the foraminiferal host regarding reduced isotope uptake. In conclusion, all pesticides had a negative impact on the holosymbiont, with the host showing varying degrees of sensitivity towards different types of pesticides.

Bioavailability of metals in coastal lagoon sediments and their influence on benthic foraminifera

Coastal lagoons experience removal and leaching of metals due to seasonal fluctuation of salinity coupled with pH and dissolved oxygen variability. Benthic foraminifers are susceptible to seasonal variation in physicochemical conditions. Assessment of bioavailable fraction of selected metals in sediments along the salinity gradient of the largest brackish lagoon in Asia- Chilika was carried out. Further, population density and abnormality index of foraminifera in the sediments were calculated to understand the influence of bioavailable metal on benthic foraminifera. Metal concentrations were higher in the low salinity regions and decreased towards the high salinity regions. This suggests river discharge controls the metal input and distribution in the lagoon. Overall, metal concentrations are high in the residual fraction (F4) followed by interplay within the reducible (F2) or oxidizable (F3) fractions, except for Mn. The seasonal fluctuations of pH and cyclic oxygen deficiency intensified the leaching of Fe, Cr, Cu, Pb, and Zn in the bioavailable fraction in the low salinity region of the lagoon. The presence of metals in bioavailable fractions impacted the normal growth of the abundant Ammonia species. Despite low bioavailable metal concentrations, higher morphological abnormalities were observed in the high salinity regions due to higher energy conditions near the sea. Therefore, abnormalities in the benthic foraminifera are attributed to bioavailability of metals from sediments and natural stress conditions in the coastal lagoon environment.

Test deformation and chemistry of foraminifera as response to anthropogenic heavy metal input

Benthic foraminifera are sensitive to environmental changes and widely used as tools to monitor pollution. Rising numbers of deformed tests are often used as indicator for elevated levels of heavy metals, but little is known about the relation between heavy metal incorporation into foraminiferal tests and the formation of test deformities. Here, two sediment cores from the south-eastern North Sea are compared, regarding the occurrence of deformed foraminiferal tests, foraminiferal test chemistry (ICP-MS) and bulk sediment Pb content (XRF). The total abundance of deformed foraminiferal tests seems not to align temporarily with historical heavy metal pollution. Therefore, we suggest that foraminifera react with test deformation to other environmental stressors than the studied heavy metals. Test chemistry reflects historical increased bulk sediment heavy metal content, despite a slight temporal offset. We propose that Pb (and Cd) are only incorporated into foraminiferal tests above a yet to be defined threshold of pollution.

Benthic foraminifera as potential ecological proxies for environmental monitoring in coastal regions: A study on the Beypore estuary, Southwest coast of India

The benthic foraminiferal diversity index was computed from Beypore estuary sediments. The abundance and diversity of Quinqueloculina lata, Textularia agglutinans, Haplophagmoides canariensis, and Quinqueloculina stelligera were dominated by stress-tolerant taxa such as Ammonia tepida, A.parkinsoniana, Nonion grateloupi, and N. scaphum in the estuary. The small-size foraminifera probably perished in a juvenile stage because of the high temperature and low salinity that prevailed in the ecosystem. The dominance of stress tolerant benthic foraminifera and absence of Elphidium species in the estuary suggest the prevalence of hypoxic (low-oxygen) conditions. The consistent low-diversity index of foraminifera indicates that the ecosystem is moderate to highly stressed ecologically in the Beypore estuary. The application of benthic foraminifera as a bioindicator for assessing the environmental stress in the Beypore estuary is key in monitoring these fragile coastal ecosystems.

Heavy metal assessment in surface sediments off Coromandel Coast of India: Implication on marine pollution

The present study investigates the distribution of heavy metals (Fe, Cd, Co, Cr, Cu, Ni, Zn and Pb) in the surface sediments along the Coromandel Coast of Bay of Bengal as an indicator of marine pollution. Pollution indices such as Contamination factor (CF), Enrichment factor (EF) and Geo-accumulation index (I) were performed to assess the spatial distribution and pollution status of the study area. The heavy metal concentration in the study area is closely associated with grain size and organic matter. Both geoaccumulation index and metal contamination factor indicate that the sediments are free from contamination with regards to the metals Cr and Ni, followed by uncontamination to moderate contamination of Co, Cu and Zn. However, sediments are found to be extremely polluted with respect to Cd and Pb. Factor analysis reveals that the accumulation of these heavy metals in the shelf sediments are due to anthropogenic inputs from the adjacent land area.

Morphological deformities of benthic foraminifera in response to nearshore pollution of the Red Sea, Egypt

The Red Sea encompasses a wide range of tropical marine habitats that are stressed due to anthropogenic activities. The main anthropogenic activities are hydrocarbon exploration and important trading harbors. This work aims to assess the influence of the Red Sea coastal heavy metal contamination on the marine meiofauna along three sites (Ras Gharib, Safaga, and Quseir). Eight heavy metal (Cu, Cd, Zn, Pb, Cr, Co, Ni, and Mn) contents are considered in four benthic foraminiferal species (Elphidium striatopunctatum, Amphistegina lobifera, Amphisorus hemprichii, and Ammonia beccarii). Quseir Harbor showed the highest level of pollution followed by Safaga and Ras Gharib sites. The analyzed benthic foraminiferal tests displayed noteworthy high concentrations of Cd, Zn, and Pb in Quseir Harbor which could be attributed to the anthropogenic activities in the nearshore areas. Some foraminiferal tests exhibited abnormalities in their apertures, coiling, and shape of chambers. A comparison between normal and deformed foraminiferal tests revealed that the deformed ones are highly contaminated with elevated heavy metal contents such as Fe, Mn, Ni, and Cd. Statistics in addition to geo-accumulation and pollution load indices reveal a whistling alarm for the Quseir harbor. The present data are necessary to improve conservation and management of the Red Sea ecosystem in the near future.

Organic matter from benthic foraminifera (Ammonia beccarii) shells by FT-IR spectroscopy: A study on Tupilipalem, South east coast of India

Fourier Transform Infrared Spectroscopy (FTIR) was used to study the variations in organic matters of benthic foraminifera (Ammonia beccarii) from four samples collected from beach environments from brackish environments along Tupilipalem coast (South east coast of India). Common absorption bands were observed as peaks in the range of 3600–3400 cm⁻¹, 3000–2850 cm⁻¹, 1750–1740 cm⁻¹, 1640–1600 cm⁻¹, 1450–1350 cm⁻¹, 885–870 cm⁻¹ and 725–675 cm⁻¹ in all the shells of Ammonia beccarii. The FTIR spectrum of station-1 represents the presence of alkanes (CH₃) and alkyl halide (C—F stretching) with absorptions at the range 1385–1255 and 1350–1150 cm⁻¹ were observed and ether (C—O stretching) absorption band was observed at stations 1 and 3 with wavenumber of 1115 cm⁻¹ and 1117 cm⁻¹ respectively. Alkynes C—H bend was observed at station-1 with the wavenumber of 667.43 cm⁻¹. The shifting of peak positions in all the samples is could be due to presence of organic matter in the samples. Satellite remote sensing and field observation data revealed that the river mouth at Tupilipalem coast was closed by a sand bar. Consequentially, this waterbody may affect the species diversity.

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Positions of the sampling locations were identified using a hand-held Garmin Global Positioning System (GPS).

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Foraminifera from the sediment were obtained using a mixture of Bromoform and Acetone.

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The functional groups present in the benthic foraminifera shells were recorded in the spectral range of 4000–400 cm⁻¹ using an FT-IR Spectrophotometer.

Heavy metal pollution monitoring with foraminifera in the estuaries of Nellore coast, East coast of India

A total of 112 bottom water and sediment samples collected at fixed stations in pre-monsoon and post-monsoon from four estuaries (Pennar, Uppateru, Swarnamukhi, and Kalangi) showed foraminiferal test abnormalities in heavy metal concentrations (Co, Cr, Cu, Fe, Mn, Ni, and Pb). Low diversity of fauna was due to the predominance of a limited number of opportunistic species capable of achieving high densities in adverse environmental conditions and the reduction in the number of species intolerant of such conditions. In this study, classification of 54 common species according to their distribution is presented. Approximately 15 species showed quite low diversities at stations 23-27 and 44-51. Because of the effect of heavy metal pollution in these estuaries, drastic changes in the number of species and diversity of foraminifera were observed. These changes in foraminiferal species and the increase in test abnormalities are proxies of environmental stress on the estuarine ecosystem.

Testing benthic foraminiferal distributions as a contemporary quantitative approach to biomonitoring estuarine heavy metal pollution

Biomonitoring of estuarine pollution is the subject of active research, and benthic foraminifera are an attractive group to use for these purposes due to their ubiquitous presence in saline water and wide diversity. Here, we describe a case study of biomonitoring using benthic foraminifera in the French Mediterranean lagoon, Bages-Sigean lagoon. In this case, the major pollutants of interest are heavy metals in the sediment, particularly contaminated by Cu and Cd derived from industrial and agricultural sources. The foraminiferal assemblages of the Bages-Sigean lagoon are typical of normal paralic environments, but unusually almost completely lack agglutinated forms. The density of benthic foraminifera was shown to be more influenced by the sediment characteristics rather than heavy metal pollution. However, the relative abundance of Quinqueloculina bicostata was shown to increase in the most polluted areas and we propose that this taxon may be used as an indicator of heavy metal pollution.

Benthic foraminiferal assemblages and trace element contents from the lagoons of Orbetello and Lesina

The Italian marginal areas of Orbetello and Lesina lagoons have been investigated in order to assess the response of benthic foraminifera to the trace element contents in the sediments. The investigated lagoons are deeply affected by high values of trace elements. The lagoon of Orbetello shows the highest values of Cd, Cu, Ni, Pb, Zn, and Hg, whereas the lagoon of Lesina exhibits the highest values of As. On the basis of the trace element contents, both lagoons can be considered from moderately to strongly polluted. Biotic and abiotic factors have been investigated with multivariate technique of statistical analysis. On the basis of the trace element content, the cluster analysis reveals the occurrence of three main clusters. These natural groupings are also confirmed by the principal component analysis. The comparison of trace element concentration patterns with the Foraminiferal Abnormality Index shows a possible influence of these pollutants on the benthic foraminiferal assemblages. Generally, the highest concentrations of trace elements in the investigated areas are remarkably mirrored by the highest percentages of deformed specimens.

Assessment of trace element contents of chicken products from Turkey

Due to the consumption of chicken and chicken products in Turkey at high ratio, trace metal content of chicken and chicken products from Turkey were determined by atomic absorption spectrometry after microwave digestion. The accuracy of the method was confirmed by analysis of standard reference material (NIST SRM 1577b Bovine liver). Trace element content in various parts of chicken samples and chicken products were to be in the range of 0.10-114 microg/g for copper, 0.25-6.09 microg/kg for cadmium, 0.01-0.40 microg/g for lead, 0.10-0.91 microg/g for selenium, 0.05-3.91 microg/g for manganese, 0.06-0.10 microg/g for arsenic, 0.01-0.72 microg/g for chromium, 0.01-2.08 microg/g for nickel, 0.01-0.02 microg/g for cobalt, 0.10-1.90 microg/g for aluminium, 1.21-24.3 microg/g for zinc, 2.91-155 microg/g for iron. The levels of lead in some analyzed chicken products were higher than the recommended legal limits for human consumption.

Evaluation of trace heavy metal levels of some fish species sold at retail in Kayseri, Turkey

Cd, Ni, Cr, Zn, Cu and Pb concentrations of muscle tissue of 61 fish samples belonging to six fish species (Sparus auratus, Pomatomus saltatrix, Sarda sarda, Engraulis encrasicholus, Sander lucioperca, Scomber scombrus) retailed in Kayseri, Turkey were determined by flame atomic absorption spectrometry after wet digestion. Cd concentrations of at least 31 fish samples (50.8%) and Pb concentrations of at least six fish samples (9.8%) exceeded the corresponding Turkish permissible limit of 0.05 and 0.2 mg kg(-1) respectively whereas Zn concentrations of 11 fish samples (18%) exceeded the Turkish Food Codex limits of 50 mg kg(-1) for Zn. Cu concentrations of all fish species analyzed (100%) were below the corresponding Turkish legislations of 20 mg kg(-1). No limits were established concerning Ni and Cr concentrations in fish by the Turkish governmental authorities.